1. Field of the Invention
This invention relates to a structure of plasma display panels.
The present application claims priority from Japanese Application No. 2004-129361, the disclosure of which is incorporated herein by reference.
2. Description of the Related Art
Some typical display apparatuses include a plasma display panel (hereinafter referred to as “PDP”) having a hermetically sealed discharge space filled with a discharge gas in which discharge is produced for generating an image, for example.
Such a type of display apparatus is conventionally equipped with a high-spattering-resistant protective layer that covers the display-space-facing area of a structural component of the display apparatus for the purpose of preventing the structural component of the display apparatus from being spattered by plasma generated at the time when a discharge is produced in the discharge space.
Materials for forming the protective layer for protecting a dielectric layer need to have certain characteristics, such as long life, strong resistance to spattering, and a high coefficient of secondary electron emission for the purpose of reducing the discharge starting voltage. Typically magnesium oxide (MgO) is used as the material.
In recent years, the foregoing display apparatuses have been popularized, particularly, in the form of a large-sized slim flat display for displaying a HDTV image, and thereby an increase in definition and an increase in screen size have been promoted. For furthering the advance of popularization, a reduction in power consumption, an increase in brightness and an increase in light-emitting efficiency are required.
A conventional display apparatus proposed for responding to those requirements has a protective layer including cesium which is a simple substance in the alkali metal series, or alternatively a cesium layer formed on a protective layer.
Such a conventional display apparatus is disclosed in Japanese Patent Laid-open Publication 2000-67759, for example.
However, cesium being a simple substance has conductivity and lacks the so-called memory effect of accumulating wall charges. Thus, the simple substance cesium is unsuitable for alternative-current plasma display panel.
Further, the simple substance cesium shows very high activity and immediately undergoes oxidation in the atmosphere, resulting in cesium hydroxide. For this reason, cesium has the disadvantages that the deposition of a layer in the manufacturing process is difficult and the layer of the simple substance cesium is very susceptible to spattering.
Therefore, the development of a plasma display panel having a reliable protective layer capable of causing a further improvement in discharge characteristics is required.